[ad_1]
The Mu COVID-19 variant has received increased attention in recent weeks and was recently designated as a “variant of interest” by the World Health Organization (WHO). But is Mu more dangerous than the Delta variant that is fueling the latest wave of infections in the United States?
The Delta variant has spread to more than 170 countries around the world since its first identification in India in October 2020, becoming dominant in many regions.
In the United States, for example, Delta is now fully dominant, accounting for more than 99% of new COVID-19 cases, according to figures from the Centers for Disease Control and Prevention (CDC).
According to the CDC, the Delta variant causes more infections and spreads faster than earlier forms of SARS-CoV-2, the virus that causes COVID-19.
Studies show that Delta is highly contagious, possibly more than twice as contagious as the previous variants.
There is also some evidence to suggest that Delta could cause more serious illness than previous variants in unvaccinated people.
Some research has shown that individuals infected with Delta, which has been listed as a “variant of concern” by the CDC, appear to have viral loads 1,000 times higher than those seen with previous variants.
Although COVID-19 vaccines are effective in reducing Delta infections, as well as serious illnesses, revolutionary cases can still occur. People who are fully vaccinated with breakthrough infections can still pass the virus on to others, although they appear to be infectious for a shorter period of time.
Delta has multiple mutations on the virus spike protein. This particular set of mutations makes the variant much more efficient when it comes to binding and entering human cells, hence why it is so contagious.
Much less is known about the Mu variant, which the WHO added to its list of “variants of interest” (VOI) on August 30.
The variant, which was first identified in Colombia in January 2021, has now been confirmed in more than 40 countries around the world and in all 50 US states.
WHO has designated Mu as a VOI due to significant epidemics in South American countries such as Colombia and Ecuador, as well as parts of Europe.
But in the United States, Mu only made up about 0.1% of new infections in the week ending September 11, according to the CDC. And the proportion of new cases caused by the new variant has been declining since July as Delta has become more dominant. The CDC has yet to list Mu as a VOI.
The Mu variant has several mutations in the spike protein, with early research indicating that it may be more resistant to vaccines or natural immunity than previous variants (although the extent of this is not yet clear).
But WHO officials have said the Delta variant is of much more pressing concern due to its highly contagious nature.
Maria Van Kerkhove, the agency’s technical manager for COVID-19, said in a virtual press conference last Tuesday: “The Delta variant for me is of most concern due to the increased transmissibility.”
“In some countries the proportion of cases with the Mu variant is increasing,” Van Kerkhove said. “But in other countries the proportion of Mu is declining. Where Delta is, Delta takes over very quickly.”
Dr Mike Ryan, head of the WHO health emergency program, told the press conference that any new variant must compete with the “best in class”, which is currently Delta. This variant tends to “outperform” other variants, he said, although they are better able to escape the protection offered by vaccines or natural immunity.
Earlier in September, White House chief medical adviser Dr Anthony Fauci said U.S. health officials were monitoring Mu closely while downplaying the threat posed by the variant.
“We are paying attention, we are taking it all seriously, but we do not see it as an immediate threat at the moment,” Fauci said at a press briefing on September 2.
John P. Moore, professor of microbiology and immunology at Weill Cornell Medical College, previously said News week that while Mu has some “disturbing mutations” it is not spreading widely in the United States.
“I have seen very few studies on its properties because it hasn’t been widely studied yet. The bottom line is that it just isn’t spreading much.”
The fact that Mu doesn’t spread as quickly as Delta could mean that the new variant will be phased out, according to Moore.
“One of the things we’ve learned with Delta is that it’s done away with less transmissible variants,” Moore said. “It is the more heritable variants that dominate. And everything else becomes less and less of a problem. Unless Mu has unique transmissibility properties, and that would be surprising as this has not been seen until then. now. It’s survival of the fittest from a virus perspective. “
And even though Mu is found to be more resistant to vaccines than other strains, experts say the injections currently available are likely to still be effective in protecting against serious illness.
Jesse Erasmus, PhD, director of virology at HDT Bio and acting assistant professor at the University of Washington School of Medicine in Seattle, told WebMD: “A preprint study (not yet peer reviewed) has come out on September 7 and indeed demonstrates that Mu is slightly more resistant to the vaccine than the beta variant. “
“When we talk about vaccine escape, we have to be very careful that we are talking about an infection escape, not a serious illness. Even against the most resistant variant of the vaccine, vaccines always protect against disease. “
iStock
[ad_2]
Source link